I have a number of keys on my keyring - screen door, main door, garage door, some random key that I don't know where it goes, etc. When I purchased the house the previous owner placed different coloured zip-ties on each key for identification and snipped the tails off. This is pretty clever, but adds to the bulk of the keyring. What is another good way to identify the keys? Not all the heads are the same size and shape, but some are3

I have a number of keys on my keyring - screen door, main door, garage door, some random key that I don't know where it goes, etc. When I purchased the house, the previous owner placed different coloured zip ties on each key for identification and snipped the tails off. This is pretty clever but adds to the bulk of the keyring. What is another good way to identify the keys? The heads are assorted shapes and sizes.